My new Knoppix 3.7 installation-to-hard drive is really enjoyable. So many major improvements.

Apt & Thunderbird are resisting. On Jan.24 I noticed that the Thunderbird maintainer at Debian said he had uploaded the T'bird 1.0-3 package on Jan.17.
So I asked my system: "apt-get install -t unstable mozilla-thunderbird" and it elegantly delivered and installed a perfect copy of T'bird 0.9-6.
The "target mirror" which Apt is pointed at by our Kpx3.7 by default (see /etc/apt/source.list) which is <ftp.de.debian.org> confirmed today, yes, T'bird 1.0-3 *is* in the unstable stream, and 0.9-6 in the testing stream.
So this evening I again gave my system the same apt-get command. And the reply: "You have the latest, 0.9-6".
Changed the command slightly: "apt-get mozilla-thunderbird/unstable". Got the same reply.
Can anyone tell me what kind of gremlin's at work here? Anyone seen an advisory? A fix...maybe point to another mirror?
Chada